Proposition 1.2 (Section 2 and Proposition 5, [1]}) 
Let \(B\)  be a left cancellative left semi-brace. Then, the additive semigroup \((B,+)\)  is the direct sum \(G+E\) , where \(G:=B+0\)  is a subgroup of \((B,\circ )\)  and \(E\)  is the set of idempotents of \((B,+)\) , which also is a subgroup of \((B,\circ )\) . Moreover, \((G,+,\circ )\)  is a skew left brace and \((E,+,\circ )\)  is a trivial left semi-brace.

